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Hi all,
so i managed to swap the Boxford Lathe for the Sherline 2000 Mill.
After doing some tests with it, im happy with the results so far.
I spent about 7 days working out the best feed rate for certain tooling i bought.
I will get some pics up very soon but for now, does anybody else have one of these mills and what's there experience with them
Cheers
Stu
So ive been doing some machining today and for some reason when i did a 15mm deep pocket at a 0.2 DOC at 400 Feed with spindle at max 2800 RPM.. the circle i wanted to pocket isnt a circle at all. its more ov an oval and it seems the top and bottom of the circle is off...
Think this may be caused by a inapropriate amount of backlash. im going to take the motors off tomorrow and see what if any couplers are on it
Stu
so ive manged to backlash compensate on Mach 3 for now..
but ive come across another hinderance
i move 5mm.... it moves 5.1mm so on and so forth!
what could this be?
If you move 10mm does it move 10.2mm? If so the value entered for the steps/mm is incorrect - so check that.Quote:
Originally Posted by cooliced
What values did you enter for the backlash compensation?
i will check on the steps/mm
these are my compensation settings
y = 0.300
x = 0.100
z = 0.160
Totally unacceptable but there are not anti-backlash couplers on the axis yet... why in gods earth would you not use these
Hi. Don't have a mill but have a Sherline lathe. Expensive but a very awsome and capable bit of kit and have turned SS and cast iron with ease. The 3 jaw chuck is only about a 1/4 thou out and now 10 years use. Being made in the US they are imperial, check the lead screws, they do metric versions but imperial is most common which would go a way to explain 5.1 (5.08) if the conversion is 2.5mm per 1/10th inch instead of 2.54 (just an idea?). Anyway, definately the best small lathe money can buy.
http://www.sherline.com/CNCfaq.htm
stuck, have you asked them? I have found their team obliging and helpful gentlemen.
Tom
yeah its a imperial mill converted to cnc.. i dont do imperial to be honest.
Is there any settings in Mach 3 to do this?
I absolutely love the mill but i need something bigger at some point...
Thanks for the help
my motors are set to 320 steps per mm
If it is indeed 5TPI screws then you should set the motor steps per revolution to 314.9606:
You say 320 step/mm and 5mm pitch, so 5*320=1600 step/rev. That implies your motors are set to 1/8 microstep... 5TPI is 25.4/5=5.08mm. So 1600/5.08=314.96... step/mm.
Try that and measure it over a greater distance. What are you using to measure the travel?
0-25 mm Digital Dial Indicator DTI 0.01mm Large LCD
simular to that but from inline
thanks i will try that.
Make sure the DTI is precisely parallel to the slide, otherwise you may get a false reading. Off by about 11° is enough to account for a 0.1mm discrepancy in 5mm.
i had it viced using the bolt hole on the back and squared the vice so it should have been good.
So i put the settings in that you suggested and it is spot on tbh. i cut a 15 hole and it was actually round! im very happy and thank you for your help
According to the Sherline website:
http://www.sherline.com/setupins.htm
The manual imperial mill gives 0.050" as the distance of one turn. So this makes it 20 tpi, ie a pitch of 1.27mm. I also say sthat the Sherline steppers are 0.9 degrees step
http://www.sherline.com/CNCfaq.htm
ie, 400 steps per revolution = 1.27 mm which means for you, 314.9606 steps per mm.
Yours are set to 320 per mm which will give 1.2903 mm per revolution.
So if you programmed a 5 mm move (Mach 3 will think this is 1600 steps), and it moved 1600 steps, you would actually move 1600/314.9606 = 5.08 mm which is what I origionally suggested.
I am not famiiar with Mach 3. Is there a way of entering steps per mm fraction? Waht you really want is 320 per 1.27mm. If you used 315 steps per mm you would be 0.125mm out over a meter. According to the specs, the longest travel is the X axis with is 9 inches = 228mm, 315 steps per mm would make full travel 0.029 mm too long. Not very much! The answer for exact acuracy if there is such a thing is to routinely scale all cad files by 0.9987 and use 315 steps per mm or order and fit metric screws.
Does that help? Anyway, I'd love one. I have an old (but very good nick) Isel mill, extruded, about A4 cutting area, preloaded ball screws, recirculating bearings and servo driven, home brew software. But I've lost some garage space and something may have to give at some point, all very sad.
Tom
Tom, thank you very much mate, im not the best at these sort of calculations and you got it spot on. ive been cutting things for the last 5 days and its been ace!
Thank you again.
Next part of the build for this little monster is a coolant booth!
Btw, ive been cutting aluminium at 400 Feed and a D.O.C of 0.3 at 2800 RPM, seems to be solid so far, might try 0.5mm D.O.C tonight:whistling:
No problem mate and brilliant! I've always been tempted to get a Sherline spindle and motor for my CNC. They are really well made and have a lot of power and run quietly. I currently use Kress, no load speed good but if you need any power, speed drops dramatically which makes it really hard to get the speed right. And I find they get very hot. With a Sherline spindle you've got very good speed control and it would be quite happy with a 1/8" end mill or a 2 inch fly cutter. My lathes 12 years old now, never adjusted, origional belt and still perfect. Made 8, 48mm diameter cast iron wheels with it once, it never complained a bit. Never tried to swap the one on the lathe in case of accidents though. They are very nice machines! It should be happy with mild steel but yes, coolant will help a lot, with ali or brass you can use just water or if you don't push it too hard, compressed air. Anyway, it's all about having fun!
This is my rather over engineered beasty:
Some tests during a "rebuild"
http://www.youtube.com/watch?v=8MmqX...eature=related
Some quick moves to test for following errors after the "rebuild". It has one serious limitation, the data packets are RS232 so that limits complex moves to about 10 a second, circles or arcs are just one command so can be quick. MACH3s innovative use of a parallel port leaves it in the dust (which there is an awful lot of!).
http://www.youtube.com/watch?v=KGCIQ...eature=related
Tom
forgot to mention i was using a 6mm roughing endmill
i would love a fly cutter, just cant find anybody that sells the sherline ones
I used to get my bits from here:
Millhill Supplies Ltd.
Unit 37, Broton Drive, Halstead, Essex C09 1HB, UK
Tel: ++44 (0) 1787 472236, Fax: ++44 (0) 1787 477797
E-mail: [email protected]
Website: www.millhillsupplies.co.uk
That was a few years ago, their website seems live! Chronos do a small cheap set, OK for light cuts!
Thanks for the link mate. gonna be ordering some bits from them soon.
So after posting in the single flute thread, i thought i would push my machine with a number of different endmills
with a 3 flute carbide 6mm endmill, i was pushing 1.5mm DOC at 350mm/min <- this i was very happy with
With a 2 flute HSS 6mm endmill (cheap, from ebay for 3 quid), i managed to get 3mm DOC at 225mm/min <- even more happier with this..
I cant wait to get the single flute carbide ones. hopefully go 3-4mm deep at 300mm/min would be the best thing ever..
Also im gonna start a dedicated youtube channel for my projects
Thanks for looking
Stu
Hi Mate
No problem, just make sure you pm me to point me at your youtube, interested to see how you get on! I'm black5f on YT as well, basically , a black 5 is a steam engine!
Make sure your endmills are capable of plunge cutting if thats what you need to do. Endmills will give a flat face, they have a flat end, but cannot always cut nicely in plunge and on hard materials and can skate a bit before they bite. One of the teeth needs to extend all the way across the centre, so they are not symetrical when looked at from the bottom. Slot drils will plunge and slot but don't give such a clean bottom to the slot. Most end mils plunge nicely but beacause they are flat, I find you get a neater finnish on blind slots if the plunge is taken a bit gentler. At the end of the day you just have to play with speeds and feeds till your happy with the finnish. Try some nickle silver, it's nice to cut, chips nicely and doesn't tarnish. Sounds like your having fun!
Tom
Or at the model railway club I'm a member of it was tea with no milk and 5 sugars!Quote:
Originally Posted by black5f
Single flute cutters are good at plunging, but I still use ramping (spiral toolpaths) on the router. As long as the ramp angle isn't really steep it's much better.Quote:
Originally Posted by black5f
Oh yes, even better! My very very old motion card wont do that, 2D circles at 1/2 meter a second,xy yz xz no problem, spirals have to be done in small xyz interpolated steps, RS232 = sloooowwww. Which is why I'm really interested in a cheap pid servo controller doing 480Mbits instead of 9600 baud.Quote:
Originally Posted by Jonathan
Tom
i put a 10 degree ramp over 20mm, and tboth the 2 and 3 flute cut loverly, alot less chatter..
i will start getting pictures up and videos tomorrow..
Ive been busy tonight moving my spare room shop around a bit to give me more room and space for my composites work..
Thanks for the replies guys
Stu
After sorting the spare room out fomr more space and a general tidy up i have started my YT video series with an intro
http://www.youtube.com/watch?v=V-x8wS8LN5Q
With all the stock i have, i have been wanting to mill some vice clamps instead of using nuts and bolts...
http://i200.photobucket.com/albums/a...1-12163647.jpg
http://i200.photobucket.com/albums/a...1-12191338.jpg
http://i200.photobucket.com/albums/a...1-12191330.jpg
Still more to do but i wanted to get the basic shape done before dinner.
I will keep this thread updated more and more as i go
Stu
Nice! Although now I must have a Sherline head on my mill, sick of my 2 x deafening Kress heads! They do a 10,000 rpm one now I see.
Tom
Yeah, looking over the Sherline website, they do a 10k spindle pully set..im not sure wether it would reduce the power...
Ive kind took a back seat until i can get a probe setup, i keep finding myself getting fustrated that my cuts are sometimes off.
Altho i do have another video to post.
thanks for looking
Stu
http://www.youtube.com/watch?v=yobyXwZXwaE
final video for the vice clamp.
Going to get the new drip tray sorted and get making some chips
thanks
stu
Those are far too shiny. Did you just use a buffing wheel to polish them? The finish looks very even in the video.
If the pulleys just change the ratio of the existing motor then you will have the same power (minus a fraction for reduced efficiency) at 10k, but proportionately less torque as Power=torque*angular velocity.Quote:
Originally Posted by cooliced
Hi Jonathan,
I used a bit of 12000 Grit Wet and Dry with WD40, then Brasso lol
Ive seen a Rock Tumbler with walnut shells and it produces stupidly good results strait from the machine!
So with the 10k Pulley set would it be advised to take smaller cuts due to the drop in torque?
Thanks again
Stu
Yeah, but only use the 10k on small diameter bits (1/8 and smaller like 1/16), and, you will have to adjust the end float as well (sherline recommend this) to avoid heat build up in the bearing. You will loose about 3/4 of the torque you have right now. The current setup will probably handle a 1.5 inch throw flycutter, continuously for hours on end. I have no experience with running them fast. Unless you really need very small bits regularly and high feeds, I would actually stick with this set up, it has a long history of being very good and reliable. Unlike cheaper stuff, Sherline do seem to know what they are doing and how the machines perform so if they say adjust endfloat, best to do it. For occasional use of small bits, just take it easy? Just carefully cleaned the scroll of my Sherline 3 jaw chuck and bit down on some accurate ground bar, the run out is less than 0.0005" (0.012mm or resolution of my dial gauge). It's about 15 years old!
Tom
I absolutely love this machine, and it will stay even when i get the bigger bench top from SPG.
Thanks for the comments
Stu
Glad to hear that. In a disposable world, I have things I expect to chuck away, and stuff, that well, I don't really own, I am just the keeper for the time being!
Tom
OK this is going up for sale tonight! With everything!
£600 takes it
PM me if your interested!
Stu
So i did these plaques for a mate, not overly happy with them.
http://i200.photobucket.com/albums/a...712_151751.jpg
I did 45 degree hatching with the engraving and it has steps in it.
im using a 90 degree spot drill for this as i was advised it would be ok.
D.O.C 0.5mm
spindle speed: 2800
Feed: 120 MMPM
3hrs 40 mins to complete... (forever)
Anybody have any suggestions on how to do this quicker? Also would the 10k sherline pulley set be better for me
http://i200.photobucket.com/albums/a...ps71df1775.jpg
Broke it, gonna be a while till i can get a replacement sent from the US
FFS
On another note, ive moved into a proper unit now and got all my stuff setup...
Thinking about a bigger mill PCNC1100 or something like that! unfortunatly has to be single phase but ill keep looking
Stu
i have a triac for sale.
http://www.mycncuk.com/forums/items-...c-pc-sale.html
Would you guys class this as commercial cnc mill?
Would it be able to do small production runs continually?
I wouldn't class it as a commercial mill, but it's about the best desktop single phase (run off a 13amp plug) mill out there.
i've run my triac continuously for 16 hours with only a short break, and that was for me.